PowerPoint PresentationSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16I. Protein exportII. Structure and composition of the nuclear pore complex (NPC)III. Mechanism of translocation through the NPCTHE HETEROKARYON ASSAYIMPORTINEXPORTINIMPORT EXPORTRanGTP-binding and import cargo releaseRanGTP-hydrolysis and export cargo releaseNUCLEUSCYTOPLASMNUCLEUSCYTOPLASMEXPORTINGTPGTPGDPGDPIMPORTINIMPORTCARGOIMPORTCARGOEXPORTCARGOEXPORTCARGORan-GTPNPCcargoDomain Organization of Importin βStructure of the exportin Cse1 with RanGTP and cargoTHE METAZOAN NPCRout et al.(2000) JCB 148:635THE YEAST NPCInteraction between nuclear transport receptors and the FG-repeats within the NPCInteraction between nuclear transport receptors and the FG-repeats within the NPC14Organization of the NPC15Specificity Models of the NPCBrownian Gate Selective Phase ‘Oily SpaghettiSUMMARYI. Short signals target proteins into and out of the nucleusMany proteins shuttle: regulationII. Many transport events are mediated by the importin β superfamily of importins and exportinsIII. Directionality is conferred by nuclear RanGTPRan-GTP mediates substrate release (importins) or substrate binding (exportins)per import/export cycle ~ only one GTP is hydrolyzedRanGTP gradient provides energy for transportIV. NPC functions as facilitated diffusion channelFG rich repeats provide docking sites for transport
View Full Document
Unlocking...